Peripancreatic Enhancing Lesion in a Cirrhotic Patient

Abstract

Question: A 74-year-old white man with a history of decompensated alcoholic liver disease was referred to our clinic for further management of his cirrhosis. The patient initially presented to an outside hospital 2 months prior with increasing abdominal girth and confusion. Small, nonbleeding esophageal varices were visualized on upper endoscopy. Doppler ultrasonography revealed a portal vein thrombus with cavernous transformation. The patient was initiated on warfarin. He presented to us for a second opinion. Physical examination revealed an elderly, ill-appearing gentleman with anicteric sclera, shifting dullness and bilateral lower extremity edema. Laboratory testing was notable for a total bilirubin of 0.8 mg/dL, alanine and aspartate aminotransferases 190 and 150 U/L, respectively, and alkaline phosphatase 1000 U/D. International Normalized Ratio was prolonged (on warfarin) at 4.2; creatinine was 1.1 mg/dL and albumin 3.2 g/dL. Triphasic computed tomography of the abdomen and pelvis demonstrated a large peripancreatic lesion enhancing on portal venous phase with resultant mass effect on adjacent structures (Figure A). What is the diagnosis? Look on page 324 for the answer and see the Gastroenterology web site (www.gastrojournal.org) for more information on submitting your favorite image to Clinical Challenges and Images in GI. Triphasic computed tomography of the abdomen reveals an 8.2 × 6.5-cm portal vein aneurysm containing subacute thrombi. Compression of the remnant thrombosed portal vein demonstrates mass effect from the aneurysm (Figure A). Cavernous transformation of the liver secondary to portal vein thrombosis can be seen distal to the aneurysm (Figure B). Coronal and sagittal views further demonstrate the extent of the aneurysm (Figures C, D). Portal vein aneurysm is a rare clinical entity that mainly occurs at bifurcations and confluences of the portal venous system, both intra- and extrahepatically. In patients without preexisting liver disease, it may result from congenital malformations, such as intrinsic weakness of the vein wall or diverticular remnant of a primitive portal precursor.1Lau H. Chew D.K. Belkin M. Extrahepatic portal vein aneurysm: a case report and review of the literature.Cardiovasc Surg. 2002; 10: 58-61Crossref PubMed Scopus (0) Google Scholar In cases of acquired portal vein aneurysm, portal hypertension secondary to cirrhosis is the most frequently reported cause. Portal hypertension initially leads to compensatory medial hypertrophy that is eventually replaced by fibrous tissue with weak tensile strength.2Rafiq S.A. Sitrin M.D. Portal vein aneurysm: case report and review of the literature.Gastroenterol Hepatol. 2007; 3: 296-298PubMed Google Scholar However, portal vein aneurysms are still rare in patients with known cirrhosis, suggesting that an existing congenital abnormality may be present for portal hypertension to result in aneurysmal dilation.1Lau H. Chew D.K. Belkin M. Extrahepatic portal vein aneurysm: a case report and review of the literature.Cardiovasc Surg. 2002; 10: 58-61Crossref PubMed Scopus (0) Google Scholar Because most patients are asymptomatic, portal vein aneurysms are generally found incidentally on abdominal imaging. Conservative management with serial imaging is appropriate for small aneurysms in asymptomatic patients without concomitant portal hypertension or cirrhosis. Complications from portal vein aneurysm include thrombosis, rupture, and symptoms related to compression on adjacent organs such as the common bile duct, duodenum, and vena cava. Rupture of portal vein aneurysm is unusual because of low portal venous pressure, but the risk of rupture does increase in the presence of portal hypertension. Patients with portal hypertension and portal vein thrombosis may benefit from surgical shunts to reduce portal pressure and prevent progressive dilation of the aneurysm.3Brock P.A. Jordan P.H. Barth M.H. et al.Portal vein aneurysm: a rare but important vascular condition.Surgery. 1997; 121: 105-108Abstract Full Text PDF PubMed Scopus (69) Google Scholar This particular patient had several risk factors for acquired portal vein aneurysm, including decompensated alcoholic cirrhosis with portal hypertension as well as radiographic evidence of chronic pancreatitis. Given the patient's age, multiple comorbidities, and rapid deterioration, it was the family's request not to pursue aggressive measures. His anticoagulation with warfarin was discontinued.